Process of treating petroleum oils



W. M. BURTON ET AL PROCESS OF TREATING PETROLEUM OILS Mar; 13, 1923.

Fild Mar.

2, 1916 2 sheets-sheet l IIIIIIlIw IIIIIII 'Mar. 13, 1923..

W. M. BURTON ET AL PROCESS OF TREATING PETROLEUM OILS 2 sheets-sheet 2 Filed Mar.

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N MW

Patent Mar. 13,, 1

an M. woman, or CHICAGO, AND'EDGAR m. CLARK, or ALTON, ILLINOIS,

ASSIGNORS TO STANDARD OIL TION' OF INDIANA.

COMPANY, OF WRITING, INDIANA, A CORPORA- PROCESS OF TREATING PETROLEUM OILS.

' Application filed March 2 1916. Serial No. 81,665.

To all whom-2'23 may concern:

Be it knownthat we, WILLIAM M. BUR- won and 'EDGAR M. CLARK, ;citizens of the United States, residin at Chicago, in the 5 county of Cook and tate of Illmois, and Alton, in the county of Madison and State of IlllIlOlS, have invented a new and useful Improvement in Processes of Treating Petroleum Oils, of which the following is a specification. ur invention relates to certain improvements in the art of distilling hydrocarbon 011s. More particularly the invention is concerned with the destructive distillation or crackin of relatively heavy petroleum oils to pro uce therefrom lighter oils. The prlmary object of the present invention is to provide a method of operation by which relatively high cracking temperatures may be obtained without the usual concomitant condition of proportionately high pressures. By our present process this desirable result is obtained, and likewise numerous secondary advantages of considerable practical importance. 1

The invention will be more fully understood from the following detailed description taken in connection with the accom panying drawing, in which Fig. 1 illustrates diagrammatically in side elevation one form of apparatus for carry- 1ing out the process, and Fig. 2 is an enar stil Referring first to. the drawing, the numere] 10 designates the drum of a suitable still, which as illustrated is of the horizontal tubular type, the tubes designated 10, being located within the furnace 11. A stack 12 is connected with the furnace as by an underground flue 13. The external fittin of the still include the usual gage 14 and'd r awoff 15, the latter being connected through the furnace wall. with the lowest point of the rear tube-header so that the drum and tubes maybe completely drained, as is well understood.

Leading from the still at'an upward inclination is a combined va or outlet pipe and reflux condenser or deep legmator 16 of proper dimensions, and for increasing the (1 vertical broken section through the condensing capacity of the latter we prefer-- ably surmount it with a radiator 17. From the upper end of the radiator a vapor pipe 18 leads downwardly to a Water-cooled condenser 19, and below the latter is arranged a receiving drum 20 for the condensate. It is to be noted that in the arrangement shown the entire system including the still, dephlegmator, radiator, condenser and receiving drum is in open communication throughout. The receiving drum is provided with a valved liquid drain 21 and a valved gas escape pipe 22, and .by this construction the contents of the and maintained at any desired pressure. At the end of the dephlegmator 16 adjacent to the radiator 17 a supply pipe 23 1s tapped'thereinto which pi e may be split into two branches 24, 25, tlie former bein provided with a check valve 26 and contro valve 27, and the latter, which is employed as a drain only, having a cut-ofl valve 28. The supply branch 24 will lead to a pump or storage chamber or reservoir havlng a pressure sufiicient for the introduction of the fluid into the dephlegmator, as will later ap ear.

mmediately below' the elbow of the dc phlegmator there is mounted within the drum 10 a funnel 29 (Fig. 2) carried by an inclined pipe 30 which projects into the upstanding end 31 of the. rear vertical trunk 32 by which the rear tube header is connected with the drum.

In the use of the apparatus above described for carrying out our new process, the still will be charged with a petroleum oil of relatively high boiling point, for instance a. stock havin a boiling point of its lowest substantial raction approximating 600 F. at atmospheric ressure. The still will then be fired and t e contents heated up too point at which distillation proceeds slowly under a pressure of upwards of four and preferably about vseven atmospheres, this pressure being maintained not only u on the liquid in the still but preferably a throughout the system under t a control of the valved gas escape pipe 22, as in the patent to Wil mm M. Burton, one of the present applicants, N 0. 1,049,667, of'January system may be brought to 65 7th, 1913, The temperature of: the liquid body and the vapors in the still will then be approximately 750 F, the temperature of the vapors being progressiyely less along the length of the dephlegmator.

l lhen this condition has been reached webegin to feed in through tbesupply pipe 24:, a stock of oil of mean boiling point substantially lower than that of the stock in the still, for instance bottoms from the redistillation of crude gasolene made by the proc ess of the Burton patent before referred to, Such. bottoms rouge in boiling point (at at= mospheric pressure) from about 100 to 500 or thereabcuts. Under the pressure of seven atmospheres maintained'in the still and its connected condenser the boiling point of this stock would be about 600 to 700 F, which would be too low to efiect any considerable cracking, especially since these bott/orns have already been subjected to one cracking operation the result of which is to render them quite refractory Asthis cold stock, entering through. the pipe 24, passes downwardly through the deplilegmator and becomes mixed with the reflux condensate therein, its temperature is radually raised, the rise being suilicient to firing the stream almost to its boiling point at the time itleaves the lower end of the dephlegmetor todrop into the tunnel 29, The lighter portion of the mixed stream, includ ing substuntielly all of the in-fed stock is thereupon instantly flashed into a vapor by coming into contact with the hot body of oil, This, vapor instead of remaining at its boiling point temperature of 600 to 700, becomes instantly superheated by the liquid body of the still charge and the high-boiling-point vapors thereof, being thus brought to the tern Jerature of the still in spite of the fact that its normal boiling point temperatureunder the pressure obtaining in the still is materially below the temperature of the latter. This superbeating of the vapors of the low-boiling-point stock by the liquidbody and vapors of distillation of the highboiling-point stock, is the result aimed at by our process, Under these conditions the temperature required for cracking the lowboiling-poiut materiel is obtained without the employment of proportionately high and without resort to superheating tubes, fieshmlates, red-hot refractory earth masses molten metal baths, or any of the recognized. expedients for superheating vapors, Whatever proportion of the mixed stream entering the funnel 29 fails to be Va poriaed therein is conducted directly downward into the hot tubes 10, being thereby subjected immediately to the highest temperature aveilable,

Our process may ordinary apparatus pressures,

be carried out with the used for pressure distill lotion and therefore commends itself to pee practical refiners as involving no untried expedients but only safe and economical metlu ods of proven value It is to be noted that in the operation set forth above the charge of relatively high boilingpoint stock within the still is itself subjected to a cracking operation simultaneously with its use as a superheater for acting upon the lighter stock fed in, It will be apparent that the exact extent of this cracking of the still charge will depend upon the nature of tliat charge, i. e., it may be composed of such refractory constituents as to dissociate only to a small degree under the temperature and "pressure conditions obtaining in the still, or it may be of such a nature as to crack at the ordinary rate under these conditions.

lit will be understood that the cracked vapors of the iii-fed stock will ,pass outwardly through the dephlegmator, and thence to the condenser and receiving drum in the usual. manner.

While we have described in considerable detail one specific manner of carrying out the novel steps of our process, it is to be understood that this description is illustrative only, and for the purpose of making our invention more clear, and that we do not intend that our invention shall be construed as limited to these details except in so far as we have included such limitations within the terms of the following claims in which it is our intention to claim all novelty inherent in our process as broadly as is permissible in view of the prior art.

What we claim as new and'desire to secure by Letters Patent is:

1. The process of distilling petroleum. hydrocarbons which consists in heating a liquid body of such hydrocarbons above its atmospberic boiling point under a pressure of upwards of tour atmospheres to efiect distillation thereof, and feeding into such liquid body from an extraneous source a fresh stock of hydrocarbon having a boiling point-under the prevailing pressure lower than the tern perature of the liquid body, thereby supereatingz and cracking the infed material.

2. The process of cracking refractory petroleum hydrocarbons which have previously undergone one cracking operation which consists in beating a liquid body of hydrocarbons having a boiling point above that of the refractory stock to a temperature exceeding the boiling-point of the latter, and introducing the refractory stock from an extraneous source into such heated mass, thereby superheating and cracking the some.

- 3. The process of distilling hydrocarbons for the pyrogenesis of lower boiling point hydrocarbons which consists in maintaining a body of the hydrocarbons in a receptacle under super-atmospheric pressure, and flowing a vstream of said hydrocarbons through a heated zone to said receptacle, thereby maintaining a vaporizing temperature in the receptacle, and supplying to said flowing stream from an extraneous source hydrocarbons having a boiling point under the prevailing pressure lower than that of the body of hydrocarbons.

4. The process of distilling hydrocarbons for the pyrogenesis of lower boiling point hydrocarbons which consists in maintaining a body of the hydrocarbons treated in a receptacle under superatmospheric pressure, flowing a stream of said hydrocarbons through a heated zone to said receptacle, thereby maintaining a vaporizing tempera ture therein, cooling the vapors evolved to condense their heavier constituents and supplying this condensate to said flowing stream together with additional hydrocarbons -from an extraneous source having a boiling point under the prevailing pressure below that of the body of hydrocarbons.

5. The process of distilling hydrocarbons for the pyrogenesis of lower boiling point hydrocarbons which consist in maintaining a body of the hydrocarbons treated in a receptacle under superatmospheric pressure, flowing a stream of said hydrocarbons through a heated zone to said receptacle, cooling the vapors evolved to condense their heavier constituents, and supplying this condensate to said flowing stream.

6. The method of decomposing hydrocarbons for the pyrogenesis of lower boiling point hydrocarbons, which comists in maintaining a body of hydrocarbons treated in liquid state in a receptacle under superatmospheric pressure, flowing a stream of such hydrocarbons through a heated zone to said receptacle efl'ecting a separation from the treated hydrocarbons subsequent to their passage through the heated zone of constituents intermediate between the hydrocarbons treated and the desired low boiling products and supplying the intermediate constituents 'to said flowing stream.

WILLIAM M. BURTON. EDGAR M. CLARK.

In presence of J. D. R001, A. J. SCHWARTZ. 

